The Sault Ste. Marie Tribe of Chippewa Indians formally asked the U.S. Army Corps of Engineers to reject Enbridge's permit for the Line 5 tunnel beneath the Straits of Mackinac, presenting treaty rights and environmental concerns during a one-hour virtual consultation Monday, Aug. 10.

Tribal subject matter experts outlined environmental, cultural and legal objections to Lt. Col. Donald Lew and Corps staff, according to a Sault Tribe newsroom statement. The Tribe urged the Corps to complete a thorough treaty rights analysis before reaching its permitting decision.

The consultation came together fast. The Tribe requested the meeting Thursday, Aug. 6, and was offered the virtual session four days later, a limited timeframe before the Corps reaches its permitting decision, the Tribe said.

The Corps permit is one of the last federal approvals Enbridge needs before construction can begin on the proposed tunnel, which would replace the existing dual 20-inch pipelines that have crossed the Straits lakebed since 1953 with a single 30-inch line inside a concrete-lined tunnel bored through bedrock. Originally estimated at $500 million, the project's cost has ballooned into the billions, with construction now projected to run into 2030, according to Bridge Michigan.

The Sault Tribe is a signatory to the 1836 Treaty of Washington, which guarantees Anishinaabe tribes the rights to fish, hunt and gather in the Straits area, according to Indian Country Today. The Tribe maintains the federal government has a trust responsibility to tribal nations and an obligation to uphold those treaty rights throughout the permitting process.

The federal consultation lands in a shifting regulatory landscape. On July 31, the Michigan Supreme Court issued a 6-1 decision vacating the Michigan Public Service Commission's 2023 approval of the tunnel, sending the project back to state regulators for a broader environmental review. A new MPSC hearing could come in 2027, according to the Michigan Advance. Enbridge spokesperson Ryan Duffy called the ruling "unfortunate in that it adds an additional delay to the permitting process for the Great Lakes Tunnel, which is designed to protect the Great Lakes and ensure the ongoing safe, reliable and efficient delivery of energy to our region," the Michigan Advance reported.

That ruling does not affect the state environmental permits issued July 15 by the Michigan Department of Environment, Great Lakes and Energy (EGLE) and the Department of Natural Resources, but those permits prohibit disturbance of cultural resources unless Enbridge holds all required approvals, including an effective PSC order and a Corps permit, MLive reported.

Not everyone opposes the project. Mike Smith, executive director of the UP Construction Council, said in a July 15 statement responding to the state permits that union members across the Upper Peninsula support the tunnel because it "protects the Great Lakes, creates and supports great jobs and great paychecks, and it's a big part of our energy mix," The Center Square reported.

The Corps has not publicly commented on the Tribe's request or indicated a timeline for its permit decision. Enbridge did not have an immediate statement specific to the Aug. 10 consultation. The Tribe said it expects the Corps to weigh the concerns raised during consultation and will provide updates as the process moves forward.

EGLE is expected to rule by Sept. 30 on Enbridge's separate request to discharge up to 6 million gallons of treated wastewater per day into Lake Michigan during tunnel construction, Bridge Michigan reported. The Sault Tribe and Sacred Waterways have also previously announced a public kayak flotilla and rally opposing Line 5 at Kiwanis Beach in St. Ignace on Saturday, Aug. 29.